Technical data

8 TROUBLE SHOOTING
The following table details possible unit faults, their probable cause and suggested remedies. For any
other problems not immediately recognisable and/or for technical assistance, call an Authorised York
Service Centre.
Fault Probable Cause Remedy
Differential oil pressure switch cuts
on, break circuit.
Defective differential pressure
switch operation.
Check switch operation, replacing if
necessary.
Low oil level as a result of circuit
leakage.
Determine location of leak and
repair.
Start up with cold oil. Check oil heater operation.
Compressor lube circuit
malfunction.
Call an Authorised York Service
Centre.
Unit operates continuously, but
without cooling.
Low refrigerant charge. Top up charge.
Drier/filter clogged. Replace drier/filter.
Loss of efficiency in one or both
circuits.
Check compressors and replace if
necessary
Suction line freezes. Temperature rise of thermostatic
valve out of calibration.
Increase setting.
Check charge
Excessive noise. Vibrating pipework. Secure pipework.
Check pipework retainers.
Thermostatic expansion valve hiss. Top up charge.
Check filter/drier, replacing if
necessary.
Noisy compressor. Check condition of valves.
Bearings have seized; replace
compressor.
Check that compressor retaining
nuts are tight.
Low compressor oil level. One or more gas or oil leaks in
circuit.
Identify and eliminate all leaks.
Mechanical damage to compressor. Call an Authorised York Service
Centre.
Faulty crankcase oil heater. Check electrical circuit and
crankcase heater element
operation, replacing any defective
components.
035B40022-000 8-1